The present invention relates generally to electronic printing processes and more specifically to a method and apparatus for electronically separating a colored original into a plurality of images.
In the cloth printing process, a colored original is separated into images carrying one of the colors of the original. The separated images are used to provide a printing pattern with which a sheet of cloth is printed. In a prior art printing process, the separated images are developed in separate photographic films, thus needing as many photographic films as the number of colors used in reconstructing the original image. Since the separated images were developed on separate films, the size of the films must be equal to each other in order that they exactly overlap one upon another. Because the film must be dimensioned to accommodate the maximum size of the separated images, most of the separated images occupy only a portion of the entire area of the film, thus resulting in wastage of film.
A primary object of the invention is therefore to reduce the wastage of photographic films by developing separated images on different areas of a single film.
A further object is to provide an improved method and apparatus in which a colored original is recorded in the form of coded signals and means are provided to selectively detect particular code signals in a predetermined sequence as the recorded information is being retrieved.
In accordance with the invention, a colored original which is painted with a plurality of predetermined colors is first scanned along each of a plurality of line paths within the original to detect the light reflected therefrom. The detected light is then separated into three light beams of one of the three primary colors and the separated beams are each converted into corresponding electrical signals which are in turn compared with a set of reference voltages derived from color samples carrying the same colors as used in painting the original. Each of the line paths so scanned is divided into a plurality of line segments carrying one of the colors in the original. The line segments are each translated into a first characterizing code which represents the color of the segment and a second characterizing code which represents the length of that segment, or the time between transitions of colors along the line path. These first and second characterizing codes are recorded in sequence in a recording medium such as a magnetic tape. In the subsequent process, the recorded information is transferred to a shift register. The shift register is shifted in such manner to decode a set of first and second characterizing codes at one time. A first-code detector is provided to selectively detect the first code representing the same color within the line path. A scanner is provided to scan across the surface of a photographic film. The second code is decoded into the length of each line segment to measure the position of color transitions from the start of each line path. Only those line segments which are characterized by the detected first code are recovered. The first code of the non-recovered line segments are subsequently detected by recirculating the binary data in the shift register, and recovered on a separate portion of the film.
The present invention can be used to develop an image of the same pattern in different areas of a photographic film by repeatedly detecting the same first code, and modified to synthesize a new image by superimposing a plurality of images.